Pump unit and pump

Abstract

To provide a pump unit and a pump capable of stably expanding an inner cylinder and improving transfer efficiency, without using shape regulation means.SOLUTION: A pump unit comprises: an outer cylinder that expands and contracts in an axial direction, and is made of an elastic body; an inner cylinder that is provided on an inner peripheral side of the outer cylinder, and made of an elastic body; and a flange that is fixed to both axial end parts of the inner cylinder and the outer cylinder and forms a closed space between an outer peripheral surface of the inner cylinder and an inner peripheral surface of the outer cylinder. The pump unit supplies fluid to the closed space to expand the inner cylinder in a central axial direction, and transfers a transported object in the inner cylinder. The inner cylinder comprises rigid members that extend along an axial direction at predetermined intervals in a circumferential direction of the outer peripheral surface. The rigid members are made of a material that cannot deform in response to the expansion and contraction of the inner cylinder.SELECTED DRAWING: Figure 4

Description

[Technical field]

[0001] The present invention relates to a pump unit, and more particularly to a pump unit and a pump that utilize peristaltic motion to transport a transported object. [Background technology]

[0002] Conventionally, one type of pump known is one that transports an object by utilizing peristaltic motion, as shown in Patent Document 1. This type of pump transports an object by connecting a plurality of pump units configured to provide a double-pipe structure in which an inner cylinder is provided inside a cylindrical outer cylinder, and a fluid such as air is supplied into an annular chamber formed between the outer cylinder and the inner cylinder, thereby making the inner cylinder expandable radially inward, and changing the volume inside the inner cylinder as the inner cylinder expands. In such a pump unit, in order to stabilize the inward expansion of the inner tube, a circular shape determining means (shaper ring) is interposed between the inner tube and the outer tube, and the shape determining means deforms a portion of the circumferential area of ​​the inner tube radially inward in advance, thereby promoting radially inward expansion, and thereby stabilizing the inward expansion of the inner tube. [Prior art documents] [Patent documents]

[0003] [Patent Document 1] JP 2020-33995 A Summary of the Invention [Problem to be solved by the invention]

[0004] However, since the inner cylinder is deformed radially inward by the shape defining means even when it is contracted, the conveying path may become narrower, which may reduce the transfer efficiency. Therefore, in order to solve the above problems, the present invention aims to provide a pump unit and a pump that enable stable expansion of the inner cylinder without using conventional shape determining means and can improve transfer efficiency. [Means for solving the problem]

[0005] The pump unit for solving the above-mentioned problems comprises an outer tube made of an elastic body that expands and contracts in the axial direction, an inner tube made of an elastic body provided on the inner side of the outer tube, and flanges fixed to both axial ends of the inner tube and the outer tube and forming a closed space between the outer peripheral surface of the inner tube and the inner peripheral surface of the outer tube, and the pump unit transports the transported object in the inner tube by expanding the inner tube in the central axial direction by supplying a fluid to the closed space, the inner tube having rigid members extending along the axial direction at predetermined intervals in the circumferential direction of the outer peripheral surface, and the rigid members are made of a material that cannot deform as the inner tube expands and contracts. According to this configuration, the space on the inner periphery side of the inner cylinder through which the transported object is transferred can be closed and opened without narrowing. In addition, in order to solve the above problem, the pump can be configured to include a drive unit formed by connecting a plurality of pump units as described in claim 1, and a control device that controls the supply and discharge of pressurized medium to the pressure chambers of each pump unit constituting the drive unit and individually controls the expansion and contraction of each pump unit, thereby improving the transfer efficiency of the pump. [Brief description of the drawings]

[0006] [Figure 1] FIG. 2 is a schematic diagram of a pump. [Diagram 2] FIG. 4 is a cross-sectional view of the pump unit in a natural state. [Diagram 3] FIG. 4 is a cross-sectional view of the pump unit in an expanded state. [Figure 4] FIG. [Diagram 5] FIG. [Figure 6] 5A to 5C are cross-sectional views showing the operation of the pump unit. [Figure 7]5A to 5C are cross-sectional views showing the operation of the pump unit. [Figure 8] 13A and 13B are diagrams showing other forms of the rigid member. [Figure 9] 13A and 13B are diagrams showing other forms of the rigid member. [Figure 10] 13A and 13B are diagrams showing other forms of the rigid member. DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

[0007] The present invention will be described in detail below through embodiments of the invention. However, the following embodiments do not limit the invention according to the claims, and not all of the combinations of features described in the embodiments are essential to the solution of the invention, and include configurations that are selectively adopted.

[0008] FIG. 1 is a schematic diagram of a pump. As shown in FIG. 1, pump 1 includes a drive unit 1A that pumps the transported object, and a control unit 1B that controls the operation of drive unit 1A. Drive unit 1A can be provided, for example, in the middle of a pipe provided for transporting the transported object, integrally with the pipe, or drive unit 1A can be provided as the pipe itself. Drive unit 1A is configured by connecting a plurality of pump units 2 in series, and the operation of each pump unit 2 is individually controlled by control unit 1B. The transported object referred to here can be in any form, such as a solid, liquid, powder, or a mixture thereof.

[0009] The control unit 1B includes an air supply means 50 which supplies compressed air as a pressurized medium, a valve unit 52 which has valves for supplying compressed air from the air supply means 50 to each pump unit 2 and discharging the compressed air supplied to the pump unit 2, the number of valves being equal to the number of pump units 2, a control device 54 which individually controls each valve provided in the valve unit 52, and a circulation pipe 56 which enables air to circulate between each valve and each pump unit 2. The pressurized medium is not limited to compressed air, but may be other gases or liquids.

[0010] The control device 54 includes a CPU as a calculation means, storage means such as ROM and RAM, and input / output means. The storage means stores programs and the like for driving the pump units 2 constituting the drive section 1A, and the CPU executes processing in accordance with the programs stored in the storage means, thereby outputting signals for opening and closing the valves to the valve unit 52 via the input / output means, and causes the multiple pump units 2 to perform a pump operation simulating peristaltic motion.

[0011] Fig. 2 is an axial and radial cross-sectional view of the pump unit according to this embodiment in a natural state. Fig. 3 is an axial and radial cross-sectional view of the pump unit according to this embodiment in an expanded state. As shown in Figs. 2 and 3, the pump unit 2 includes an inner cylinder 4, an outer cylinder 6, and flanges 8;8.

[0012] FIG. 4 is an external perspective view of the inner cylinder. The inner cylinder 4 is formed by molding an elastic material that is flexible, stretchable, and deformable and has airtightness into a cylindrical shape. The material for forming the inner cylinder 4 may be, for example, a material that uses rubber as a base material. The inner cylinder 4 includes a conveying section 4A which serves as a conveying path H for the object to be conveyed, a fixing section 4B for fixing the conveying section 4A, and a rigid member 20.

[0013] The conveying section 4A is formed, for example, in a cylindrical shape with a constant thickness. The fixing section 4B is provided at each end of the conveying section 4A in the axial direction and is formed as an annular flange section with a predetermined thickness that surrounds the outer periphery of the conveying section 4A. The fixed portion 4B is formed integrally with the conveying portion 4A, and is formed in a hollow disk shape that expands concentrically radially outward at the end of the conveying portion 4A. The fixed portion 4B has a protrusion 4C formed around the entire periphery at its tip (outer periphery) that protrudes toward the conveying portion 4A (axially inward).

[0014] Examples of rubber that forms the inner tube 4 include natural latex rubber, silicone rubber, NR (natural rubber), IR (synthetic natural rubber (isoprene rubber)), BR (butadiene rubber), IIR (butyl rubber), and CR (chloroprene rubber). The inner tube 4 is not limited to a single material, and may be made of a combination of multiple materials. The material that forms the inner tube 4 is not limited to the above-listed materials, and may be any material that is airtight and elastic, and the magnitude of the elastic force may be changed appropriately depending on the transported object, for example.

[0015] The rigid member 20 according to this embodiment will be described below. As shown in FIGS. 2 to 4, the rigid members 20 are provided on the outer peripheral surface of the conveying portion 4A of the inner cylinder 4, and are arranged at equal intervals of, for example, 90° in the circumferential direction. In this embodiment, the rigid members 20 are aluminum rods having a square cross section, and are provided at the axial center of the inner tube 4 so as to extend along the axial direction on the outer circumferential surface of the inner tube 4. Note that each rigid member 20 will be described as being identical. For example, one side of each rigid member 20 is directly bonded to the outer circumferential surface of the inner cylinder 4 with an adhesive.

[0016] The axial extension length of the rigid member 20 may be set based on the axial expansion and contraction of the pump unit 2. For example, the rigid member 20 may be set to a length shorter than the distance between the flanges 8;8 when the pump unit 2 contracts in the axial direction.

[0017] In the above embodiment, the rigid member 20 has been described as an aluminum rod having a square cross section, but is not limited thereto. The rigid member 20 may be any member that does not deform in association with the deformation of the inner cylinder 4 when the pump unit 2 expands (the inner cylinder 4 expands). Not deforming in association with the deformation of the inner cylinder 4 means that the rigid member 20 can be regarded as a substantially rigid body against the force received from the inner cylinder 4.

[0018] For example, a material that itself has rigidity, such as metal, can be used for the rigid member 20. When using metal, it is preferable to use a lightweight material with low density, such as aluminum.

[0019] Furthermore, the material of the rigid member 20 is not limited to metal, but may be resin or a combination thereof.

[0020] Furthermore, the rigid member 20 is not limited to a rod-like shape such as a solid or hollow one, but may be a plate material that is structurally configured to obtain torsional rigidity and flexural rigidity, such as a honeycomb structure.

[0021] Furthermore, the cross-sectional shape of the rigid member 20 is not limited to a square, but may be other shapes such as a triangular shape, and the shape may be modified as appropriate as long as sufficient strength is obtained at the bonded portion with the outer peripheral surface of the inner tube 4 and unidirectional directivity is obtained at the bonded portion. The adhesive portion having sufficient strength means that the rigid member 20 does not fall off due to repeated expansion and contraction. Moreover, the unidirectional nature of the adhesive portion means that the adhesive portion has a long adhesive area in the axial direction.

[0022] As shown in Fig. 5, the outer tube 6 is configured as a cylindrical elastic body in which a rubber portion 6A is formed by molding a material such as low ammonia natural latex rubber into a cylindrical shape, and a plurality of fibers 6B are inserted into the rubber portion 6A. The plurality of fibers 6B are arranged, for example, in layers in the radial direction. For the fibers 6B, for example, highly elastic fibers such as carbon fibers, glass fibers, and aramid fibers can be used. The plurality of fibers are inserted into the rubber portion 6A so that the extension direction coincides with the axial direction of the outer tube 6, and restrict the expansion and contraction of the outer tube 6 in the axial direction.

[0023] The flanges 8 are provided at each axial end of the inner cylinder 4 and the outer cylinder 6. The flanges 8 include an outer cylinder attachment portion 8A to which the ends of the inner cylinder 4 and the outer cylinder 6 are fixed, and a connecting portion 8B that functions as a connecting means when connecting the pump units 2 together. The outer cylinder attachment portion 8A and the connecting portion 8B are integrally formed. The outer tube mounting part 8A is, for example, a tube formed into a cylindrical shape with a constant wall thickness. The inner diameter of the outer tube mounting part 8A is, for example, the same as or larger than the outer diameter of the conveying part 4A of the inner tube 4. The outer diameter of the outer tube mounting part 8A is, for example, the same as the inner diameter of the outer tube 6 or is formed to a dimension that allows the inner peripheral side to be fitted. An outer cylinder attachment portion 8A of one of the flanges 8 is provided with a supply / discharge hole 8D for supplying compressed air from the outside to a pressurizing chamber S (to be described later) and discharging compressed air from the pressurizing chamber S.

[0024] The connecting portion 8B is formed in a disk shape that expands in an annular shape in the radial direction from the outer periphery of the outer tube mounting portion 8A so as to be flush with an end face on one end side of the outer tube mounting portion 8A. The connecting portion 8B is provided with a plurality of bolt insertion holes (not shown) penetrating in the plate thickness direction. The bolt insertion holes are formed at equal intervals on the same circumference about the center of the flange 8, and are configured so that when the pump units 2 are connected to each other, fastening means such as bolts are passed through the bolt insertion holes, thereby enabling the pump units 2 to be connected to each other.

[0025] Further, a recess 8C is formed on the end face of the connecting portion 8B of the flange 8, into which the protrusion 4C formed on the fixing portion 4B of the inner cylinder 4 is fitted. The recess 8C is formed so as to be recessed annularly in the axial direction from the end face. The flange 8 is made of a material having a predetermined rigidity, such as, for example, a metal, hard rubber, or synthetic resin, which is not deformed by the pressure of the pressurized medium.

[0026] The inner tube 4 and the outer tube 6 are fixed to the flange 8 as follows: The inner tube 4 is assembled by passing the fixing parts 4B provided at each end of the conveying part 4A from the outer tube mounting part 8A side of the flange 8 to its inner periphery, and then dropping the convex parts 4C into the concave parts 8C while closely adhering the fixing parts 4B to the end face of the connecting part 8B. The outer tube 6 has the outer tube mounting portion 8A of the flange 8 inserted into the inner periphery of each end, and is fixed to the flange 8 in an airtight manner by tightening from the outer periphery with a ring-shaped fixing member 17 via an intermediate member 24. As a result, a pressurizing chamber S surrounded by the inner cylinder 4, the outer cylinder 6, and the pair of flanges 8, 8 is formed inside the pump unit 2. The pump unit 2 operates by supplying compressed air as a pressurizing medium to this pressurizing chamber S.

[0027] As described above, by exposing a portion of the inner tube 4 axially outward from the flange 8 and fixing it, when the pump units 2 are connected to each other, the inner tubes 4;4 of adjacent pump units 2;2 can be brought into close contact with each other, and a continuous conveying path H can be formed while maintaining airtightness between the connected pump units 2.

[0028] In the pump unit 2, the larger the inner diameter of the inner cylinder 4, the wider the conveying path H can be, and the conveying efficiency can be improved. Also, by setting the outer diameter dimension of the inner cylinder 4 and the inner diameter dimension of the outer cylinder 6 so that the distance between the outer peripheral surface of the inner cylinder 4 and the inner peripheral surface of the outer cylinder 6 is small, the volume of the pressurizing chamber S can be reduced, and the response speed when the inner cylinder 4 is expanded and contracted can be increased.

[0029] Therefore, as described in this embodiment, by configuring the inner cylinder 4 to include the rigid member 20 on the outer peripheral surface of the conveying portion 4A, it is possible to eliminate the conventional shaper ring from the pressurizing chamber S. This allows the relationship between the inner cylinder 4 and the outer cylinder 6 to be freely set, for example, by setting the dimensions so that the outer peripheral surface of the inner cylinder 4 approaches the inner peripheral surface of the outer cylinder 6 when the dimensions of the outer cylinder 6 are used as a reference, or by setting the dimensions so that the inner peripheral surface of the outer cylinder 6 approaches the outer peripheral surface of the inner cylinder 4 when the dimensions of the inner cylinder 4 are used as a reference.

[0030] As shown in FIG. 6, the pressure P of the compressed air supplied to the pressurized chamber S acts perpendicularly on the outer peripheral surface of the inner cylinder 4, the inner peripheral surface of the outer cylinder 6, and the flanges 8;8 which define the pressurized chamber S, and acts on the inner cylinder 4 as a force causing it to expand radially inward (in the direction of the central axis), on the outer cylinder 6 as a force causing it to expand radially outward, and on the flanges 8;8 as a force pressing axially outward.

[0031] Therefore, the force that the pressure P exerts on the flanges 8;8 may act as an obstruction to the force pulling the flanges 8;8 in the axial direction as the outer tube 6 expands, thereby obstructing the expansion of the inner tube 4 and the outer tube 6 in their respective directions. Therefore, the ability to set the outer and inner diameters of the inner tube 4 and outer tube 6 so that the distance between the outer surface of the inner tube 4 and the inner surface of the outer tube 6 is reduced means that the area enclosed by the outer circumference of the inner tube 4 and the inner circumference of the outer tube 6 at the flange 8 can be reduced, thereby improving the operating efficiency of the pump unit 2.

[0032] The operation of the pump unit 2 according to this embodiment will be described below. Note that in the following description, the operation of the inner cylinder 4 will be mainly described. As shown in FIG. 6, when the supply of compressed air to the pressurized chamber S of the pump unit 2 is started, the compressed air pressurizes the inner circumferential surface of the outer cylinder 6, the outer circumferential surface of the inner cylinder 4, and the flanges 8;8, which define the pressurized chamber S, in an orthogonal direction. As a result, the outer cylinder 6 starts to expand radially outward, and the inner cylinder 4 starts to expand radially inward.

[0033] The compressed air supplied to the pressurizing chamber S presses the conveying section 4A including the rigid member 20 of the inner cylinder 4 radially inward with the same force. Since both ends of the inner cylinder 4 are fixed to the flanges 8;8, the area between the flanges 8;8 is pressed by the compressed air, but in the part where the rigid member 20 is attached, deformation is only possible between each axial end of the rigid member 20 and the flange 8, and in the part where the rigid member 20 is not attached, deformation is possible between the flanges 8;8.

[0034] Therefore, when the supply of compressed air to the pressurized chamber S begins, the portions of the inner cylinder 4 where the rigid members 20 are not attached begin to deform radially inward before the portions where the rigid members 20 are attached, and the intermediate portions between the rigid members 20 in the circumferential direction begin to change radially inward the most (see FIG. 7). The portions that begin to change radially inward occur between the rigid members 20, 20, four portions in this embodiment.

[0035] As shown in FIG. 7, when the supply of compressed air to the pressurizing chamber S continues and the pressure in the pressurizing chamber S further increases, the part that first started to expand radially inward reaches a vertex, and then the part that started to expand toward the central axis J moves in a bending manner.

[0036] Furthermore, when compressed air is supplied to the pressurized chamber S and the pressure P within the pressurized chamber S increases, as shown in Figure 3 (b), the inner surfaces of the inner cylinders 4 come into close contact with each other, and the conveying path H is essentially blocked. At this time, the pump unit 2 is in a state of being most contracted in the axial direction due to the action of the outer cylinder 6 whose axial expansion is restricted.

[0037] In this way, by providing the rigid member 20 at a predetermined position of the conveying section 4A, which is configured as a stretchable elastic body, it is possible to change the rigidity of the conveying section 4A, and when the inner tube 4 expands, it can always expand at a portion where the rigidity has not increased, thereby blocking the space serving as the conveying path H.

[0038] Also, in this embodiment, the rigid member 20 has been described as being made of a material that does not substantially deform in response to deformation caused when the inner tube 4 expands. On the other hand, looking at the function of the rigid member 20 described in the above embodiment, it is also possible to make the rigid member 20 out of an elastic material that is harder than the inner tube 4, rather than making it out of a material that does not substantially deform. However, if the rigid member 20 is made of an elastic material, it will deform in response to the expansion and contraction movement of the inner tube 4, and it has been confirmed that this may affect the stable expansion and contraction movement of the inner tube 4. In view of these, it is preferable that the rigid member 20 is made of a material that does not substantially deform when the inner cylinder 4 expands.

[0039] The outer cylinder 6 is not limited to the one described in the above embodiment in which expansion and contraction in the axial direction is restricted and expansion and contraction (expansion and contraction) is possible only in the radial direction. For example, it may be one that expands and contracts only in the axial direction, without expanding and contracting in the radial direction like a bellows.

[0040] The intervals at which the rigid members 20 are arranged in the circumferential direction are not limited to uniform intervals of 90°, and they may be arranged at uniform intervals at other angles. The intervals at which the rigid members 20 are arranged in the circumferential direction are not limited to uniform intervals, and they may be uneven. The term "uneven" as used here means that they may be arranged periodically to form a predetermined pattern in the circumferential direction, or may be arranged non-periodically.

[0041] In addition, the rigid member 20 has been described as a single member extending from one end side to the other end side of the outer tube 6. However, for example, a plurality of rigid members 20 shorter than the rigid member 20 shown in FIG. 4 may be arranged in a row as shown in FIG. 8(a), or may be arranged at one end side and the other end side in the axial direction when a single rigid member 20 is provided at each position in the circumferential direction as shown in FIG. 8(b).

[0042] In addition, it is preferable to round the ends, for example as shown in Figure 9, so that the ends on one axial end side and the other axial end side of the rigid member 20 come into smooth contact with the inner tube 4 when the inner tube 4 expands.

[0043] In addition, the rigid member 20 is not limited to a straight rod shape. For example, when the inner tube 4 is in a natural state, it is separated from the surface of the inner tube 4 as shown in Fig. 10(a), and when the inner tube 4 expands, it may have a curved shape such as an arc shape so that both ends are smoothly in contact with the surface of the inner tube 4 as shown in Fig. 10(b). [Explanation of symbols]

[0044] 1 pump, 1A drive unit, 1B control unit, 2 pump unit, 4 Inner cylinder, 4A Transport part, 4B Fixed part, 4C Convex part 6 Outer cylinder, 6A Rubber part, 6B Fiber, 8 flange, 8A outer cylinder mounting part, 8B connection part, 8C recess, 8D supply and exhaust hole, 17 fixed member, 20 rigid member, 24 intermediate member, 50 air supply means, 52 valve unit, 54 control device, 56 flow pipe H conveying path, J central axis, P pressure, S pressure chamber.

Claims

1. An outer cylinder made of an elastic body that expands and contracts in an axial direction; an inner cylinder made of an elastic body and provided on the inner circumferential side of the outer cylinder; a flange fixed to both axial ends of the inner cylinder and the outer cylinder, the flange forming a closed space between an outer peripheral surface of the inner cylinder and an inner peripheral surface of the outer cylinder, A pump unit that supplies a fluid to the closed space to expand the inner cylinder in a central axial direction, thereby transporting an object in the inner cylinder, The inner cylinder is The bearing includes rigid members extending in the axial direction at predetermined intervals in the circumferential direction of the outer circumferential surface, A pump unit characterized in that the rigid member is made of a material that cannot be deformed in response to the expansion and contraction of the inner cylinder.

2. A drive unit configured by connecting a plurality of pump units according to claim 1; a control device that controls the supply and discharge of pressurized medium to and from the pressurizing chambers of each pump unit that constitutes a drive section, and that individually controls the expansion and contraction of each pump unit.

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